Information from the Buzzards Bay NEP for planners, analysts, and the public.

Turn on Map Layers

There may be a delay on displaying data depending on your connection speed. Check only one box below at a time. This map shows data only for mainland Buzzards Bay towns (Wareham to Westport). The new vs. old FEMA map changes for Bourne and Falmouth are available as kml files at the bottom of this panel. Google Earth must be installed on your computer to open the Bourne and Falmouth KML files.

Floodplain Comparisons

Old FIRM vs New FIRM
This coverage shows only areas added to the 2009-20011 FEMA flood hazard maps(red), and areas removed from the maps (blue).
Possible FIRM errors
This coverage shows apparent discrepancies between the stated base flood elevations on the 2009-2011 FEMA flood hazard maps and the BB NEP boundaries estimated for our sea level rise study based on LiDAR data ("baseline" boundary"). In plain terms, areas shaded red may be incorrectly omitted from the FEMA flood maps, and areas shaded blue may have been incorrectly added to FEMA maps. This information should be considered as a guide for further investigations. Whether a property is "in" or "out" of the floodplain can only be definitively determined by a field survey by a licensed surveyor. FEMA made some map corrections (LOMAs) in 2014 based on information we previously presented, and these corrections are included in these maps.

Google Earth Files

Please read the explanations and caveats on this page. Report map display errors or other issues to Tracy Warncke (specify browser and OS).

FEMA FIRM Floodplains, Old versus New and Possible Inconsistencies with LiDAR data

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Explanation and Caveats

This map is for informational and planning purposes only and based on data from early 2013. Resolution of flood areas may be slightly degraded (by about 1 ft horizontal) to reduce file sizes. Please go to the FEMA website for current updates or to make a map of your area. FEMA has not finalized maps for Bourne and Falmouth (and the rest of Barnstable County), so the map for those two towns should be considered draft. Some of the files are large so it may take a minute or two to download with a slow internet connection. Drag the person icon onto the road to get a street view of the area. Click the "x" (top right of the view box) to exit street view mode.

The map coverage "Old FIRM vs New FIRM" compares the 1970s-1980s FIRMs to their replacements that date from 2009 to 2013. The map coverage "BBNEP Baseline vs FIRM" compares the areas in the LiDAR data sets estimated by the BBNEP to match the FEMA base flood elevation for the site compared to the floodplain estimated by FEMA. The discrepancies between the two coverages may be the result of errors in the FEMA floodplain delineation and may warrant future study. The resolution of both these coverages have been degraded somewhat (causing shifts of 2 meters in areas) to reduce file download size. Additional analysis should be conducted with full resolution files. An explanation of these two coverages and methodologies used is contained in the 2013 draft report Discrepancies between recently updated FEMA FIRM base flood elevation boundaries and LiDAR data in Buzzards Bay.

NOTICE: The floodplain maps shown here are somewhat simplified and are for general planning purposes. They may contain errors or omissions. FEMA has provided a flood insurance program map display page for residents to make maps of their property showing the official flood insurance rate map floodplains.

Other Notes

Old FIRM vs New FIRM: This is an experimental coverage. We took a flawed older digital data coverage and, and in some areas adjusted it to better match aerial photographs to allow comparison to new maps. This methodology is imperfect, and small differences (<75 feet) between the two coverages are not necessarily significant. The resolution of this file coverage was also degraded somewhat to reduce file size to allow its display on with the Google Maps application used on this site. In the Western Half of Buzzards Bay we omitted the common areas and reduced resolution somewhat (<2 m) to improve map display speed.

More Information & Links

This floodplain maps shown here are somewhat simplified and are for general planning purposes. They may contain errors or omissions. FEMA has provided a flood insurance program map display page for residents to make maps of their property showing the official flood insurance rate map floodplains.